Traditional Japanese Herbal (Kampo) Medicines and Treatment of Ocular Diseases: A Review

Abstract

Herbal medicines have been used clinically in Eastern Asia, and traditional Japanese herbal (Kampo) formulas are approved as ethical drugs. The Kampo formulas are mixtures of the crude extracts of several herbs, each of which contains multiple components. Numerous investigators have reported that some herbal medicines are efficacious for treating several human diseases. We reviewed the literature on traditional herbal medicines and treatment of ocular diseases. Oral Orengedoku-to and Kakkon-to inhibit postoperative uveitis in humans. Oral Goshajinki-gan improved ocular surface disorders in patients with type 1 diabetes mellitus. Oral Hachimijio-gan increased retinal blood flow. Keishi-bukuryo-gan Sho might be associated with vitreoretinopathy in patients with type 2 diabetes mellitus. Oral Hachimijio-gan and Goshajinki-gan delayed lens opacification in rats and mice. Oral Sairei-to, Orengedoku-to, Senkanmeimoku-to, Scutellariae radix extract, Gardeniae fructus extract, topical Liguisticum wallichii rhizoma extract, and intravenous injection of tetramethylpyrazine, baicalin, baicalein, wogonin, and crocetin inhibited some forms of experimental uveitis in rabbits. Topical glycyrrhizinate improved allergic conjunctivitis in humans and rats. Oral crocetin improved eyestrain in humans. Oral berberine diminished experimental uveitis in rats. Baicalein, wogonin, berberine, and berberrubine inhibited in vitro expression of several cytokines in cultured retinal pigment epithelial cells. Some Kampo formulas are efficacious for treating several ocular diseases in humans and animals. Some herbal extracts and their components inhibit some forms of experimental uveitis.